Received: 26 February 2021
Accepted: 18 March 2021
First Online: 30 March 2021
: The institutional ethical committee of Tokyo Metropolitan Neurological Hospital supervised and approved all the procedures (TS-R02–016, TS-R02–033), including the use of datasets of the control subjects (PD and PSP), in accordance with the Declaration of Helsinki (amended version 2013). All the patients with SCA31 provided written informed consent for genetic analysis, the use of their clinical data for research purposes, and for publication. Under Japan law, no additional ethical approval is required for retrospective database studies.
: The authors declare no conflicts of interest associated with this manuscript.